Apparatus for burning gas



t F. OA HESS APPARATUSFOR BURNING GAS Filed July 5, 1936 3 Sheets-Sheetl v BY g.

ATTORNEY 3 Sheets-Sheet 2 Sept; 17, 1940. F. o. HEss APPARATUS FORBURNINGy GAS Filed July s, 193s' ifa Sept. 17, 1940. y F. o'. HESSAPPARATUS FOR BURNING GAS Filed July 3, 1936 3 Sheets-Sheet 3 ATTORNEYlNvENToR F/PffR/c O, H556 .Patented Sept. 17, 1940 APPARATUS Fon BURNINGGAS Frederic 0. Hess, Philadelphia, Pa., assignor to rlrhe SelasCompany, Philadelphia, Pa., a corporation of Pennsylvania ApplicationJuly 3, 1936, Serial No. 88,744

23 Claims.

tively highvcombustion and furnace temperatures, v

w transmission by radiation of a relatively large portion Aof the heatgenerated, and the maintenance of a definitely oxidizing or reducing, ora neutral combustion space atmosphere. The invention may also be usedwith advantage, howib ever, in connection with kitchen ranges, and forother purposes where the above mentioned operating conditions orcharacteristics are undesirable or not essential.

My improved method of combustion is char- 20 ,acterized primarily by thepassage of/the combustible gaseous mixture' into a combustion space,wholly or partially surrounded by a refractory wall, in a multiplicityof jets igniting'and burning in said space, and thereby forming a multi-2c plicity of separate flames or burning Jets extending alongside saidrefractory wall, which is shaped and disposed to avoid impingementthereagainst of the inner flame cone portions of the flame Jets, whilepermitting the wall portion immediately :m adjacent each flame jet to beheatedto incandescence.

For the practice of my improved method of combustion, I have devisedapparatus which in its preferred forms, comprise both circular burner 35units and elongated burner units. In the preferred form of my circulartype burner unit, the

flames, or burning combustible mixture Jets, are

arranged ina circular row coaxial with the combustion space which iscircular incross section 40 and increases in diameter with, though notin exact linear proportion with, the distance from the end of the spaceat which the combustible mixture jets enter said space, and thedifferent jets similarly diverge from the axis of the com- 45 bustionspace. While the angle of divergence from the` axis of the combustionspace at which the fuel mixture jets enters said space may vary throughquite wide limits, it is essential in general that that angle should besuch that the angle at 50 which the tip portions of the flames of fullburner capacity length diverge from the burner axis. should beappreciably less than 90, so that the combustion space, which must be'formed in correspondence with the flame shapes, will be cup 5s shaped.In such case, the angle of divergence of the flame from the burner. axisdiminishes along the length of the flame from the point at which the Jetis introduced into -the combustion space, so that the different flamesare concave to the burner axis, generally, as the ribs of an ordinaryumbrella, when in its open condition are concave to the umbrella axis asa result of the tension of the umbrella fabric.

The describedl concavity of the flames to the burner axis is due, as Ibelieve, to what may be termed the aspirating action of the flames,which makes the gaseous pressure within the zone or space surrounded bythe flames somewhat less than the gaseous pressure at the outer sides ofthe flames, so that the latter are bent inwardly by the excess of thepressure on their outer sides over the opposing pressure on their innersides. Whatever the explanation may be, the described in-bcnding of theflames is definite, and is not due to gravity or to the surroundingcombustion space wall, but exists when that wall is removed and when theburner axis is either horizontal, or vertical, and in the latter case,whether the axis extends upward or downward from the end of thecombustion space at which the combustible mixture is introduced. Theatmosphere in the portion of the combustion space atthe inner sides ofthe flames, depends upon the air-fuel ratio of the combustible mixture,since the invention permits of such efficient combustion conditions,that the oxidizable constituents of the fuel wall practically allcombine in combustion with the oxygen of the air if the mixture containsenough air for the purpose, and if not, will combine with practicallyall of the oxygen in the air content of the mixture. By suitableregulation of the air-fuel ratio in the mixture, it is thus possible tomaintain a combustion space atmosphere which is definitely reducing,definitely oxidizing, or neutral, as operating conditions may makedesirable.

The rlength of an individual flame, while dependent to some extent uponthe B. t. u. value and combustion characteristics of the i'uel in thecombustible mixture, and upon the combustion temperatures, dependsprimarily upon the Jet velocity with which the combustiblemixture isdischarged into the combustion space. In the case of any given burner,as the combustible mixture supply pressure is increased to increase thevamount of fuel burned and burner heating effect, the flames areelongated and the angle of divergence of their tips from the burner axisis diminished. The locus of the tip end of the inner cone or body ofunburned mixture portion of each flame as its length changes as a resultof a supply pressure change, is a curved line within, and to be regardedas the flame axis line, whether the flame is relatively longorrelatively short. The angle of initial jet divergence from' the burneraxis, depends upon the form and disposition of the discharge endportions of the channels or orifices through which the combustiblemixture is discharged into thev combustion space, and is substantiallyindependent of the supply pressure and flame length. The concavity ofthe flame to the burner axis increasesl as the length of the flame isincreased and i's much more pronounced when the flame yis of its maximumpractical length, than when the flame is only half that length. As shownin some of the accompanying drawings, hereinafter described, the angleof divergence of the jets discharged through diametrically opposedchannels or orifices, is about and approximately that divergence isespecially desirable from the practical standpoint in many cases. Thisis particularly desirable when the combustion space is open at itslarger end to the atmosphere,.or to a space containing an object ormaterial to be heated, and which when heated evolves vapors or gasesdesirably drawn into the combustion space proper and burned orcarbonized as the jet products `of combustion are then made oxidizing orreducing for the purpose.

Since the lateral distance from the axis oi each flame to theimmediately adjacent portion of the refractory wall should be about thesame all along the length of the flame, the contour of the inner surfaceof the refractory wall must depend upon and conform to the flame shape,and, as previously pointed out, is cup-shaped in the circular burnerunit. With the cup shape combustion space, the heat radiation is mainlyaway from the end of the combustion space at which the combustiblemixture jets are introduced, as is desirable for the transfer of h'eatto the object or space ordinarily to be heated, and also because ittends to avoid over-heating of the portion of the burner structureforming, or in heat transfer relation with, the walls of the supplyoriilces or channels through which the combustible mixture jets aredelivered to the combustion space. Those oriilce or channel walls shouldbe kept cool enpugh to prevent ignition of the combustible mixture priorto its introduction into the combustion space. To avoid or minimize theneed for water cooling, and for the ful1 attainment of the advantages ofthe invention obtainable with. high combustion chamber temperatures, theWalls .of the orifices at their discharge ends, at least, should beformed wholly or mainly of refractory material having a lower heatconductivity than any practically available metal. s

The cup shape of the combustion space of the circular burner unit ispractically desirable, also, in that it reduces the lateral displacementof the outer end portion of each ame from the corresponding portions ofthe immediately adjacent flames, and thereby minimizes the difference intemperature between the portions of the refractory wall immediatelyadjacent the flames and the cooler portions of the Wall immediatelyadjacent the spaces between the adjacent flames. 'I'he heating toincandescence ofthe refractory wall surrounding the combustion space, isdesirable not only because of the resultant high rate of heat radiationdirectly from that wall, but also because it results in higher averagegas temperatures within the combustion space, and henCe to an increasedflame radiation V.of heat, and also because it assists in maintainingthe ignition of the flames under varying conditions of operation tendingto cause the flames to blow oil'," and thereby contributes to the highturn down range which is a characteristic and advantageous feature ofthe burner unit. y

In my elongated burner unit, the combustion space is trough shaped, andthe combustible mixture Jets are introduced into the trough shapedcombustion space adjacent its bottom side or edge in two rows, and theflames in each row diverge, similarly from the plane which is midwaybetween the two rows, and may be designated as the central plane of thecombustion space. The opposing sides of the trough shaped combustionspace are not plane surfaces, but each diverges from said central planeat an angle which diminishes as the distance from the bottom of thetrough increases. With the trough shaped combustionspace, substantiallythe same relation between each flame and the immediately adjacentrefractory wall portion, is required as with the circular arrangementfirst described. A section of an elongated burner unit, transverse toits central plane,.may be identical with the diametral cross section ofa circular burner unit having supply channels of the same cross sectionand the same discharge end inclination. The fuel burning4 capacity andheating effect of the elongated unit may exceed the practical maximumobtainable with the circular burner unit, and in some cases where therequired capacity is readily obtainable with a circular unit, the

elongated unit may have certain practical advantages fromv theconstruction standpoint.

The various features of novel-ty which characterize my invention arepointed out and referred to in the claims annexed to and forming a partof this specification. For a better understanding of the invention,however, its advantages, and various specific objects attained with it,including some not hereinbefore mentioned, reference should be had tothe accompanying drawings and descriptive matter in which I haveillustrated and described some of the various forms of apparatus inwhich the principles of the present invention may be utilized.

Of the drawings:

Fig. 1 is a section of a circular burner unit, taken on the line I-f ofFig. 2;

Fig. 2 is a section on the broken line 2-2 of Fig. 1:

Fig. 3 is a sectional elevation of a somewhat diagrammaticallyillustrated furnace having a plurality of circular burner units mountedin each of two opposing walls of the furnace chamber;

Fig. 4 is a plan view of a portion of the bottom wall or hearth of thefurnace shown in Fi'g'.-3;

Fig. 5 is a section taken similarly to Fig. 1, showing a modifiedconstruction; 1

Fig. 6 is a section on the broken line 6-6 of Fig. 5;

Fig. '7 is a vertical section oi a crucible heating furnace;

Fig. 8 is a vertical section of a melting furnace;

Fig. 9 is a section of a portion of a burner having an enclosedcombustion space with a portion of its wall adapted for the transmissionof tion space into the space into the chamber A',

va radially extending flange Fig. 11 is a partial section on the lineii-il of Fig. 10;

Fig. 12 is a section of a portion of a circular burner unit having amodified form of burner tip:

Fig. 13 is a section on the line Ii-il of Fig. 12

Fig. 14 is a section of elongated burner unit:

Fig. 15 is a side elevation of a portion of the burner tip memberemployed in Fig. 14;

Fig. 16 is a section of a portion of a circular burner including specialprovisions for preventing the over-heating of' the burner iet deliverymeans; 4

Fig. l'l is an elevation partly in'section of another circular burnerconstruction;

Fig. 18 is a section on the line Il-ll of Fig. 1'1;v and ,f

Fig. 19 is a section of a portion of a burner construction comprising ahood or dome over the combustion space formed with outlets for thepassage of combustion gases from the combusheated.

The circular burner unit shown in Figs. 1 and 2, comprises a metallicburner body A including a tubular portion surrounding a burner inletchamber A', to which a combustible gas and air or fuel mixture issupplied at its lower end. through a channel A. The latter, as shown, iscoaxial with the chamber A', and passes through a spigot portion of theburner 'body externally threaded for attachment to any suitable fuelmixture supply pipe or supply chamber wall.

Adjacent, but below the upper end of its-tubular portion. the burnerbody A is formed with A:l forming a support for an annular refractorybody B. The latter has its lower portion surrounded by a cylindricalflange portion A* of the burner body which extends upward from the outeredge of the radial` portion A3. The body B may be formed of ceramicmaterial of any composition suitable for its intended purpose.

vSeated on the upper end of the tubular body portion of the burner bodyA, and extending is a burner tip member C of ceramic material which maybe of any suitable composition, such, for example, as anyof thecompositions customarily employed in making refractory ceramic burnertips heretofore known. As shown, the member C comprises a maincylindrical portion which extends into, and fits in the outer end of thechamber A', and also comprises an upper cylindrical portion C shorterand of larger diameter than the first mentioned cylindrical portion andthe chamber A. and a conical intermediate portion C2. against thebeveled upper end Al5 of the main tubular portion of the burner body A.Preferably, and as shown, the lower end portion C1i of the tip member isconical, so as to divert the fuel mixture flowing through the passage A2into the chamber A' away from the axis of the chamber in a uniformmanner.

A multiplicity of peripheral grooves C* are formed in the outer surfaceof the tip member C. Each of the grooves C4 comprises a portion parallelto the axis of the tip member and extending for the full length of themain cylindrical portion of the tip, and comprises an inclined dischargeend portion Cs extending alongside the outer surface of the taperedintermediate section C2 of the tip member to the periphery ofthe uppercylindrical burner tip pora modified form of an member anchored in theThe latter bears tion C. As is clearly shown in Fig. 2, each groove C*thus forms a gas passage or orice rectangular in cross section andhaving three walls formed by the ceramic tip C, and a fourth wall formedby the'adiacent portion ofthe rnetallic burner body A.

Preferably the tip C is anchored in the burner body A, and to that end.in the form shown in Figs. 1 and 2, the body portion of the tip memberis formed externally with a screw thread C in threaded engagement with acorresponding screw thread formed on the inner wall of the burner bodychamber A'. With theY burner tip burner body, the burner is adapted foroperation in any positionne Even when the burner is intended for useonly in the upright position shown in Fig. 1, the anchorage of thetip'member in the burner body is desirable,.since under some conditionsof use, the gas pressure in the chamber A' may well` be more thansufficient to lift the burner tip member C' out of the chamber A',unless anchored therein'.

The portion B of the inner wall or surface of the annular body B,surrounds and defines a combustion space in which the fuel mixturedelivered thereto through the channels or orifices C4, is wholly orlargely burned, and maybe described as of cup shape, and may be regardedi las comprising a circular series of surface portions or sectorsalongside the jet issuingl from one or each burner channel C. Each ofsaid surface sectors has its portion adjacent the burner body inclinedaway from the axis a of the burner `at about the same angle as theadjacent burner channel portion C5, and laterally displaced from theaxis of that channel portion. In other words, the said portion oi thesurface B may be regarded as part of a conical surface, with its apex inthe axis a, at some distance below, as seen in Fig. l, the point in thataxis at which the inclined channel portions C5, if extended, wouldintercept said axis.

The inclination' to burner orifice discharge portions C5, serves thepurpose of so locating a corresponding sector portion relatively to eachflame, or burning jet, formed by the combustion of the fuel mixturevsupplied by each orifice C4, that said surface will be heated toincandescence and with a suitably close approximation to temperatureuniformity of all portions of the surface directly alongside the flames,regardless of the actual length of the flames.

The ame lengths, in any given condition of use, will depend upon thefuelcomposition oi the constituent of the combustible mixture, and with anygiven fuelcomposition, will be longer or shorter, accordingly, as thegas pressure in the chamber A', and consequently the rate of combustionand total heating effect, are relatively great or relatively small. InFig. l, the different pairs of oppositely curved lines meeting at thepoints e', e?, e3, etc., represent the opposed outer sides of theso-called lnnercones of flames or burning Jets of different lengths,such as would ybe produced with successively higher combustible the axisa o each of the v 'said segmental portions of the wall surface B',

lines and arrows in 5 ing jct produced by the combustion of thecombustible mixture discharged through the corresponding orice C4. Asshown, the lateral displacement of the immediately adjacent portion ofthe wail B' from the flame axis e, is approxi- Vmateiy the same at allpoints along the length of said axis.

While the shaping of the surface B' relative to the flame axes e neednot be mathematically 16 exact. the general relation illustrated anddescribed'is essential to the attainment of the full advantages of theinvention. Although the combustin llames or burning jets are locatedadjacent the surface B', and are spaced away from the burner axis asdescribed, in normal operation, the entire combustion space surrounded.by the wall B', is filled with burning gases `and hot gaseous productsof combustion, which circulate in that space generally as indicated bythe curved Fig. 1. In operation, the general direction of ow toward theburner tip member C in the portion of the combustion space adjacent theaxis of the burner, can easily be defected. Apparently, hot gases arecontinuous- 3o ly passing into the portion of the combustion spacesurrounded by the flames along the portions of the flames relativelyremote from the tip member, and gases are continuously passing from saidspace portion into or between the portions of the flames nearer to theburner tip member. This, coupled with the high combustion efficiencyobtainable, permits the atmosphere in the combustion space, to bemaintained definitely reducing, oxidizing, or neutral, depending ori theair and fuel ratio of the combus- 40 tible mixture supplied. When vaporsor gases are evolved in heating an object or material located in oradjacent the larger end of the space in which said recirculation occurs,those vapors or gases may be drawn by the recirculating burn- C5 inggases and products of combustion, into admixture with the latter, andburned or reduced, depending on their character, by making the said airand fuel ratio suitable for the purpose.

For the lfull advantage of the present invention, the combustion space,cavity or tunnel surrounded by the wall B', should be of sufllcientaxial extent for the combustion of the fuel wholly, or. at least,mainly, within that space. While the inclination to the burner axis ofthe inclined portions C5 of the burner orifices and of the adjacentportions of the surface B', may be varied through a very considerablerange, it is practically essential, as has been indicated, that theangle of inclination should be s'uchthat the space' defined by the wallB' will be definitely cup shaped. The cup-shape of that spacecontributes to the maintenance of the entire wall B', or with relativelyshort flames, the zone thereof immediately adjacent the flames, at atemperature high enough to insure efficient combustion conditions andthe desired heat radiation. As will be apparent, with the cup .shape ofthe space defined by the wall B', every portion of that wall is in theposition to receive a significant amount of heat by radiation from aportion of the wall of the burner axis. Such radiation of heat to oneportion of the wall B' from another portion at the opposite side oi' theburner axis, necessarily diminishes as the space defined by the wall B',is shortened or flattened.

at the opposite side may be maintained suitably cool, as a result ofconditions, one of which is the relatively smallamount of heat which canbe transferred by radiation from the wall B' to said cylindrical surfaceas a result of the unfavorable relative disposition of the two surfacesfor transfer of radiant heat from the one to the other. A secondcondition contributing to relatively low burner tip temperatures, is thecooling ellect of the combustible mixture moving through the channelsC4. The latter. because of their individual small cross section,necessarily have a relatively large aggregate wall surface area.However, the poor heat conductivity of the refractory material of whichthe tip member is preferably formed, insures a relatively low rate ofheat flow to the relatively cool walls of the fuel channels from theuncooled and much hotter tip member surface exposed within thecombustion space.

IBurner units of the general type shown in Figs. 1 and 2 may be combinedin various ways to form a gas burner assembly or heating wallhaving a.fuel burning and heating capacity much greater than that of anindividual burner unit. For example. one wall. or each of two or morewalls, of a heating chamber or furnace may have mounted in it amulitplicity of burner units of the character shown in Figs. 1 and 2.Thus, as shown in Figs. 3 and 4, the` hearth or bottom wall, and theroof or top wall of a heating furnace E are each composed essentially o'burner units including refractory combustion space wall members BA whichare operatively identical with the part B of the burner unit shown inFigs.-1 and 2. To facilitate their assembly in the furnace chamberhearth and roof walls, the bodies BA are rectangular in outline as shownin Fig. 4, and, in each furnace wall including them, the bodies BA arearranged in side by side rows, with the adjacent bodies in each row inabuttingrelation. In the construction illustrated in Figs. 3 and 4, theindividual metallic burner body portions. corresponding to the burnerbody A oi' Figs. 1 and 2, for each row of burner units are rigidlyattached to. and may be integral portions of a gas and air mixturesupply pipe or manifold AA which extends longitudinally of, and insupporting relation with a corresponding row of burner units.

I'he arrangement shown in Figs. 3 and 4 is plainly characterized by itsmechanical simplicity and the relatively large heating capacity which itmay have, and by the uniformity with which each wall of the furnacechamber may be heated. The effectiveness of the heat distribution may beaugmented by staggering the burner units in the different rows, as shownin Fig. 4. By supplying a greater amount of fuel to the pipes AAadjacent the sides of the furnace E than to the pipes adjacent Athevertical central plane of the furnace, the side edges of the hearth androof walls and the vertical side walls of the furnace may be adequatelyheated. In the practical use of a heating chamber having burner units inits roof wall only, and of a volumetric capai'cty of some 20 cubic feet,I have found it easy to maintain heating chamber temperaturesconsiderably in excess of 2,000 F.. and to vary the rate of combustionin the individual burner llli units through a wide range, in accordancewith the desirable rate of heat absorption by the work being heated. l

In a burner unit of the general circular type illustrated in Figs/1 and'2, it is notv essential that the burner tip member should have itscylindrical body portion received in a chambered metallic burner body.Thus,y as shown in Figs. 5 and 6, for example, the' tip member CBmay bemounted directly in an axial passage B21 formed in a refractory body BBwhich replaces, and serves all the above mentioned purposes of therefractory bodies B and BA of Figs. 1-4.

In a burner in which a refractory burner tip member is mounted directlyin the refractory tunnel or body member, as shown in Figs. k5 and.

6, it is immaterial, in general, whether the combustible mixture supplyorifices C are formed in the burner tip member, as in the constructionspreviously formed, or are formed partly in y i the burner tip member andpartly in the refractory body member, or are formed wholly lin thelatter, as the orifices C10 are formed in the body BB of the burnershown in Figs. 5l and'6. As shown in Figs. 5 and 6, each orifice grooveC10 comprises a main body portion parallel to thel burner axis, and adischarge end portion in-` clined to that axis as are the orificeportions C5 of Figs. 1 and 2.

In Fig. 7, I have illustrated the use of the' present invention in afurnace'primarily adapted for heating a small crucible F, though equallywell adapted to heat an ingot or other body supported as is the crucibleF. The furnace shown in Fig. 7,` comprises a refractory body member BC,`which may be described as of inverted cup form, with its rim resting ona supporting body BC of refractory material formed with passages BC2 forthe discharge of products of combustion from the combustion space abovethe supporting member BC' and surrounded by the body member BC. Thelatter is formed at its top with an axial opening receiving a burner tipmember CC. which may be identical in form with the burner tip member Cof Figs. 1 and 2. A metallic gas supply member AC mounted on the upperend of the body member BC. is formed with a gas inlet chamber A10supplying gas to the upper ends of the orifice grooves C* of the burner.tip member CC. The base member BC' is formed at its upper side with anupwardly extending projection BCT1 on which the crucible F is seated innormal operation. The base and body members BC and BC are made separablefor the insertion and removal of the crucible, and as shown, these partsare provided with cooperating sand sealing provisions 13C'1 forpreventing leakage through the joint between the member BC and BC.

The inner wall B10 of the member BC may have its upper portion shapedexactly like the portion. adjacent the burner tip of the member B shownin Figs. l and 2. The lower portion oi' the wall B10 is advantageouslyshaped to conform to the contour of the crucibleF so as to provide asuitably shaped path of downflow along the crucible of the heatinggases.

With the burner tip above the crucible, as shown in Fig. '7, the top ofthe crucible and its contents are directly exposed to the most intenseheat radiation from the wall B10, and any molten metal which overflowsfrom the crucible. may pass immediately from the combustion chamber ofthe furnace through the outlets BC2. Except in respect to the `twofeatures just mentioned, the crucible heating action of the furnaceshown in Fig. 'I would not be modified by turning the furnace upsidedown and seating the crucible on the burner tip member CC, instead of onthe projection BC3,frorn the member BC'. Whether the crucible furnaceshown in Fig. '7, is arrangedasshown in that figure, or is inverted,full advantage may be had with it of the reducing atmosphere maintainedas described in connection with Figs. l and 2, within the portion of thecombustion space surrounded by the circular series of flamejetsalongside ythe wall B10.

In Fig. 8 I have illustrated the use of the present invention in amelting furnace which resembles the crucible. heating furnace of Fig.'7, in thatit has a burner tipm'ember CD mounted in a central passagelin the top of a refractory body member BD of inverted cup form, andhaving its rim resting on a supporting member bd. The latter serves asthe furnace hearth, and is formed with a cavity bd' in its upper side tore-l ceive the metal to be melted. As shown, the joint between themembers BD and bdis normally sealed by cooperating sand seal formingparts BD2 and bd. If the member BD is supported independently of thehearth member bd, and the latter is rotated about the vertical axis ofthe furnace, the material melted in the hearth cavity bd' may beagitatdby a stationarystir-Y ring member BB3 of suitable refractory metalextending through, and `rigidly vmounted in the body BD.

As shown in Fig. 8, an annular metallic burner body AD is imbedded inthe member BD and passes the combustible mixture to the upper ends ofthe orifice grooves C* of the `burner tip member CD. As shown, thelatter is formed with an axial passage CD open at its upper end to theatmosphere. and serving as an outlet for the products of combustionformed in the combustion space of the furnace. The hot gases dischargedthrough passage CD give up heat to, and preheat the fuel mixture passingthrough the member AD and chamber C1 of the tip member CD, whichincreases the thermal efficiency of the furnace and increases the flametemperature.

In Fig. 9 I have illustrated a form of my inventionl especiallydesirable for use in somecases, which differs from the burner shown inFigs. 1 and 2, essentially only in that the end of the combustionchamber remote from the burner tip member, is closed by a heattransmitting wall BE', and in that the burner tip member CE is formedwith an axial passage CE' serving the products of combustion dischargepurpose of the channel CD of the burner tip member CD of Fig. 9. Asshown, the wall member BE is a disc-like plate which may be formed ofquartz or of' some heat resistant metallic alloy. If formed of quartz,much ofthe heat radiated toward the wall BE from the inner wall B15 ofthe refractory body member- BE, corresponding but may be maintained atan operating tempera ture high enough for an intense radiation of heatfrom its outer surface. With `one or more burners of the generalcharacterv shown in Fig. 9

mounted in the wall of a heating chamber, as the burner units aremounted in the hearth and roof walls of such a heating chamberas isshown in Figs. 3 and 4, the atmosphere within the heating chamber cannot be contaminated by prod.- ucts of combustion, but may be formed ofinert gas or otherwise controlled, as the atmospheres in electric heatedfurnaces, and in ordinary muffle furnaces are controlled, where suchcontrol is desirable, as in certain heat treating and other industrialheating operations. The furnace chamber BF' shown in Figs. 101 and 11,is surrounded by a tubular refractory body member BF.

The furnace shown in Figs. 10 and 11, includes as its heating means oneof my improved burners of the elongated type, formed at one side, itslower side as shown, with a longitudinally extending slot BF2. As shown,the refractory body ,BF is carried by a metallic gas supply member ormanifold AF formed with lateral flanges AF' on which the member BF ismounted, and with a gas supply chamber AF2 extending into the slot BF2and open at one side to receive a portion of the burner tip member CF.The latter in transverse cross section, may be, and is shown as exactlylike the burner tip member C of Figs. 1 and 2, except that the bar-likeburner tip member CF is not anchored in the metallic burner body memberAF by the simple screw thread arrangement employed in Figs. 1 and 2.

The general operative principles of the burner arrangement shown inFigs. 10 and 11, are identical with those of the arrangement shown inFigs. 1 and 2. The discharge ends of the channels C2o are so inclined,and the slot BF2 is of such width, that the inner wall surface BF4 ofthe portion of the member BF immediately adjacent the flame formed bythe combustion of the jet issuing from any of the channels C20, will bedisplaced from the flame by approximately thesame distance at all pointsalong the length of the flame whether the latter be relatively long orrelatively short.

In the elongated burner unit of Figs. 10 and 11, the portion of therefractory wall surface B14 immediately adjacent a flame at one side ofthe central plane of the burner, receives radiant heat directly fromthat flame and adjacent flames. and from the directly opposite flames atthe other side of the central'plane. and from the opposing wall surfaceBF. In respect to the radiation characteristic just noted. the elongatedburner unit diil'ers from such a circular unit as is shown in Figs. 1and 2, only as the circular disposition of the flames and refractorywall surface of the last mentioned figures increases the radiation tothe portion of the wall surface immediately adjacent any one flame fromother flames and the opposing refractory wall portion. The eilect ofthis relative decrease in the amount of heat radiated to a portion ofthe wall BFtimmediately adjacent a flame, is compensated for. more orless. by the fact that in the .elongated burner unit the axes ofadjacent flames are parallel and not divergent, as is necessarily thecase'in the circular burner unit.

The modified circular burner unit construction shown in Figs. 12 and 13,while comprising a burner body AG which may be identical in form withthe burner body A of Figs. 1 and 2, includes a burner tip member CGdiffering in the form of its orifices or supply channels C25 from thetip member C i'lrst described. The channels C25 of the tip member CG arein the form of kerfs or slots, each extending radially of the member CGtoward its axis. merging adjacent said axis into a central axial passageC. The slots C and passage C extend longitudinally of the member CG froma short end portion of the latter adjacent its combustion space end tothe opposite end of the member.

In the elongated burner unit construction shown in Figs. 14 and 15, therefractory body n BH Ahas its opposed combustion space wall surfaces BH,each in the form of a segment of a cylinder, the combustion space beingopen at its side remote from that at which the combustible mixture jetsare introduced. Except in respect to the form of its refractory bodymember, the burner construction of Figs. 14 and 15 is generallyequivalent to the burner arrangement of Figs. 10 and 11, but differsfrom the latter in' the form of the burner tip member CH. The latter isan inverted trough shaped part having parallel sides CH externally cutaway, adjacent the open side of the `trough space'to provide recessesCH2 respectively receiving portions of the opposite sides AH of theburner body member AB. which is shown as of trough form.v The sides CH'of the member CH are each formed with a multiplicity of side by sidekerfs or slots C30, each of which forms one of the supply channels ororices through which the combustible mixture is passed into thecombustion space.

If the burner tip members CG and CH shown in Figs. 12-15 are formed ofmetal, their orifice slots or kerfs C25 and C30, respectively, maybeformed by a milling cutter. or other metal cutting machine. 'I'he tipmembers CG and CH may also be formed of ceramic material by simplemolding operations, which, as those skilled in the art will understand,may be performed in molding apparatus including metal plate core'portions forming the orifice kerfs or slots.-

As'has been made apparent. the full advantages of the present inventioncan not be obtained with burners operating at temperatures as high asare required for many industrial operadestructive of tip members of anyavailable metallic material, and even though such metallic burner tipmembers are not exposed to temperatures high enough to prevent themembers from retaining'A their general form during a considerableoperating life, the members are nevertheless subject to distortion andto surface corrosion preventing the maintenance ofthe desired orificeforms and dimensions. For certain low temperature work, however.reasonably satisfactory operating results can be obtained with metallicburner tip members, and the relative ease with which burners includingmetallic tip members of the form shown in Figs. 1215, canbe constructed.make the use of such metallic bur'ner tip members especiallyadvantageous in the case of special burner unit assemblies ofsizes andforms for which no molded refractory tip members are available.

The burner construction shown in Fig. 16 includes two expedients, eachof which may be used without the other to minimize the heating of thewalls of the vsupply orices or channels. One of saidexpedients is theheat insulation of the exposed end of a metallic burner tip member, byineans of a refractory cover CG1 therefor. The second expedient is thewater cooling of a metallic portion ofthe burner. These expedients,while of themselves complicating and adding something to the cost of theburner construction, permits the use of metallic parts forming the wallsof said channels, under burner temperature .conditions which wouldotherwise be prohibitive of the use of such metallic burner parts.

'I'he burner form illustrated by way of example in Fig. 16, is generallysimilar to that shown in Figs. 12 and 13. and includes a burner tipmember CG shown as identical with the member CG of Figs. 12 and 13, butis provided with a heat insulating cap member C610. The latter is a bodyof refractory heat insulating material suitably adapted for mounting onthe combustion space end of the metallic tip member CG, so that the heatdirectly received by said end, is only such heat as is conducted to itthrough the cap member.

The metallic burner body member AI of Fig. 16 diff ers from thecorresponding member AG of Figs. 12 and 13, in that the wall of itstubular portion is formed with an annular channel A110 surrounding theaxis of the burner and extending nearly to the combustion space of thepart AI. Inlet and outlet connections AIl1 and AIl0 are provided for thecirculation of water or other cooling fluid through the channel A110.Advantageously, the refractory body BI of the burner unit shown in Fig.16 is shaped to provide a portion BI extending over the portion of thewall of the channel A110 immediately adjacent the combustion space. Theburner construction shown in Figs. 17 and 18, comprises a burner tipmember CH, the coing bustion space end of which may be like that of theburner tip member C shown in Figs. 1 and 2 in that it comprisesa,conical surface C50 and inclined orifice grooves C01 like the surfaceC0 and groove portion C4 of Figs. 1 and 2. In the burner shown in Figs.17 and 18, however, the burner tip surface C bears against a conicalseat formed in the end of a tubular body ch of refractory materialsurrounding a shank portion C52 of the burner tip member. Said shankportion might be circular in cross section, but advantageously and asshown, is polygonal in cross section, and in .either event, is of across section smaller than that of the bore in the tubular member ch. Asshown, the latter is formed with internal axially extending ribs C03,which space the shank C50 axially of the member ch., and divide thespace between the shank and the member ch into a number of supplychannels C which may be and as shown'is appreciably ysmaller than thenumber of discharge orifices C51. As shown, the refractory sleeveelement ch is anchored on the tip member CH by means of a nut C00threaded on the shank at the inlet side of the burner.. The burnerelement comprising the parts CH, ch, land C, may be mounted in ametallic burner body generally like the metallic burner body A shown inFigs. 1 and 2, or in some analogous metallic or refractory materialburner body. As shown, the end of the sleeve ch against which the nutC00 abuts, is formed with radially extending inlet grooves C6communicating at their inner ends with the bore of the member ch.

The burner construction illustrated in part in Fig. 19, comprises aburner tip member C, a metailic body member AA, and a burner body memberBI of refractory material, all generally like the parts C, AA and BB ofthe construction shown in Figs. 3 and 4. The ypart AA is shown as formedwith a cooling fluid channel A110 in the tubular portion into which theburnertip member C extends, with inlet and outlet connec-n tions AI*1and A110 to the channel A110, as in the construction shown in Fig. 16.In Fig. 19, however, a dome or hood bi of 4heat resistant material,extendsl over the Vend of the combustion space in the burner body BIremote from the tip C, with the baseof the hood fitting around a ribbi', with which the burner body BI is provided to center the dome orhood. The latter is Iformed with ports bi for the passage of products ofcombustion from the combustion space into the space to be heated. Theburner construction shown in Fig. 19, while not limited to such use, wasprimarily devised for incorporation in the hearth of a furnace chambersuch as that shown in Figs. 3 and 4. In such use, the hood member biserves to prevent scale or furnace dust from dropping into the burnercombustion space. With the hood member bi formed of transparent quartz,much of the 'heat generated in thecombustion space may be directlyradiated into the furnace chamber, but with the hood bi formed'of heatresistant metallic alloy material, such direct radiation of heat isprevented, and the heat not carried into the furnace chamber by theproducts of combustion, will be delivered to that chamber by conductionthrough the hood, and emitted from the convex side of the latter.- 4

While as has been explained, it is ordinarily immaterial whether thegeneral direction of gas i'low in the combustion space is up, or down,or horizontal, it is convenient to refer to the portion of thecombustion space at which the combustible mixture is introduced,'as thebottom portion of said space, whether the latter be cup shaped as shownin Figs. 1 and 7, for example, or be trough shaped, as shown in Figs.and 14,/for example. Whether the combustion space is cup shaped, ortrough shaped, the supply channels through which the combustible mixtureis supplied to the combustion space open to the latter at pointsdistributed along the margin of a bottom portion of said space, and theburning Jet formed by the mixture delivered through each channel, isadjacent and alongside a section oi' the combustion chamber wall whichextends ,away from the bottom portion of the combustion space and isformed by refractory material, so that the said sections may be heatedto incandescence by the burning jets.

The present application is a continuation in part of, and claims subjectmatter disclosed Iin my prior application Serial No. 42,994, led October1, 1935. Certain combinations including a' vheat transmitting bodyinterposed between a burner combustion space and a space to be heated,shownl in Figs. 9 and 19 hereof, but not claimed herein, are claimed inmy application for patent, Serial No. Sli-8,325, illed July 29, 1940,and constituting a continuation'in part of this application. Certainnovel features of furnace construction and arrangement including burnersincorporated in the furnace chamber wall and constructed in accordancewith principles Idisclosed herein, are claimed in my copendingapplication, Serial No. 106,208, illed October 17, 1936.

While in accordance with the provisions of the statutes, I haveillustrated and described the best forms of embodiment of my inventionnow known to me, it will be apparent to those skilled in the art thatchanges may be made in said forms without departing from the spirit ofmy invention as set forth in the appended claims, and that in some casescertain features of my invention may be used to advantage without acorrespond- .ing use of other/features..

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is:

1 A gas burner having a combustion space increasing in cross sectionwith the distance from the bottom thereof, and including means forpassing a combustible air and gas mixture into said space including amultiplicity of supply channels opening to said space at distributedpoints adjacent the margin of a bottom portion of said space, so thatthe mixture discharged by said channels may form burning jetsrespectively adjacent and alongside sections of the wall of said spaceextending away from its said bottom portion, and including vrefractorymaterial forming the said wall sections so that the latter are adaptedto be heated to incandescence by said Jets, the discharge end portionsof said channels and said wall sections being relatively shaped anddisposed to avoid impingement of the inner flame cone portions of theburning jets against said wall sections and said space having a bottomwall substantially impervious to air flow into said space except throughsaid channels.

2. A gas burner as specified in claim l, in which the walls of thedischarge end portions of the mixture supply channels are formed inlarge part, at least, of refractory material.

3. A gas burner having a cup shaped combustion space and including,means for passing a combustible air and gas mixture into said space,said means comprising a multiplicity of supply channels opening to saidspace at points adjacent the bottom, and distributed about the axis, ofsaid space, so that the mixture entering the space through the differentchannels may form burning jets respectively adjacent and alongsidecorresponding sections of the wall of said space which extend away fromthe bottom of the latter, and including refractory material forming thesaid wall sections, so that the latter are adapted to be heated toincandescence by said jets, the discharge end portions of said channelsand said wall sections being relatively shaped and disposed to avoidimpingement of the inner ame cone portions of the burning jets againstsaid wall sections and said space having a bottom wall substantiallyimpervious to air ow into said space except through said channels.

4. A gas burner, tip member of refractory material comprising anexternally threaded cylin- A drical body portion and a-n enlarged headand formed with grooves, each comprising a portion at the periphery of,and extending longitudinally of, said body portion, and a portion at theside of said head adjacent said body portion, and extending to theperiphery of said head portion.

5. A gasl burner having a trough shaped combustion space increasing incross section with the distance Afrom the bottom thereof, and includingmeans for passing a combustible air and gas mixture into said spaceincluding a multiplicity of supply channels opening to said space atpoints distributed along opposite sides of a bottom portion of saidspace so that the mixture discharged by said channels may form burning`iets respectively adjacent and alongside sections of kthe side walls ofsaid space extending away from its said bottom portion, and includingrefractory material forming the said wall sections, Awhich are adaptedto be heated to incandescence by said `iets, the discharge end portionsof said channels and said wall sections being relatively shaped anddisposed to avoid impingement of the inner flame cone portions of theburning jets against said wall sections and said space having a bottomwall substantially impervious to air ow into said space except throughsaid channels.

6. A gas burner having a combustion space increasing in cross sectionwith the distance from the bottom thereof, and including means forpassing a combustible air and gas mixture into said space including amultiplicity of supply channels opening to said space at distributedpoints adjacent the margin of a bottom portion of. said space, so thatthe mixture discharged by said channels may form burning Jetsrespectively adjacent and alongside sections of the wall of said spaceextending away from its said bottom portion, and including refractorymaterial forming the said wall sections, so that the latter are adaptedto be heated to incandescence by said jets, the discharge end portionsof said channels and lsaid wall sections being relatively shapedanddisposed to avoid impingement of the inner fiame cone portions of theburning jets against said wall sections, notwithstanding a variation inthe velocity of mixture ow through said channels suiiicient to vary thelength of each jet from a minimum operative length to a maximumIoperative length at least double said minimum length and said spacehaving a bottom wall substantially impervious to air flow into saidspace except through said channels.

7. A gas burner unit comprising a body formed with an inlet chamber andwith an opening to said chamber at one side thereof and having anexternal surface at the margin of said opening and inclined away fromsaid one side, a refractory burner tip member having a portion extendinginto said opening and having an inclined surface parallel to, a-ndengaging said inclined body surface and having surface grooves, thewalls of which unite with said body to form burner outlet channels fromsaid chamber, each of said channels having a discharge end portion oneside wall of which is formed by the inclined surface of said bodymember, said body including refractory material defining a combustionspace into which said channels discharge and having combustion wallsurface portions respectively extending away from and generally parallelto the l direction of the burning jets of combustible mixture dischargedinto said comb-ustion space through the different channels.

8. A gas burner unit as specified in claim 7, in which the said chamberand burner tip member are circular in outline and have a common axis,and the said inclined surfaces extend circularly about said axis.

9. A gas burner unit as speciiied in claim 7. in which the said openinghas parallel elongated side edges and said tip member is a bar like bodyand the said surface grooves a-re formed in the opposite-side of saidbar like body, and in which there is one set of said inclined surfacesat one side, and a second set of said surfacesat the opposite side ofsaid opening and bar like body.

10. A gas burner unit as specified in claim 7,

including means for releasably securing the said burnerl tip member inthe said chamber of the said burner body. o 11. A gas burner unit asspecified in claim 7, in which the chamber entering portion of theburner tip member is circular in cross section and externally threaded.

l2. A gas burner unit as specied in claim 7, in which the saidburnerbody includes a metallic iiange portion parallel to, and spacedaway from the said side of the said chamber at which the in whichl thesaid burner saidopening is formed. and infsupporting en-` gagement withthesaid refractory material of theunit. f f

13. A gas burnerunitas specified. in claim 7,

n body includes a metallic portion formed with a cooling fluid passageexternal to the said lchamber in said body member. v, f A j 14. A gasburner unit comprising a metallic body member including a rounding aninlet chamber open at one end and having a conical end surface extendingaway fromsaid chamber` at its open end, a. burner tip member of ceramicmaterial formed with a cylindrical portion extending into said chamberthrough the open end thereof and an outer portion.` of larger crosssection with a conical surface seating against the said' conical surfaceof said body member and formed with surface grooves, eachfof saidgrooves leading from` the portion of said chamber at the inner side ofsaid tip member and having an inclined discharge end por' tion alongsidesaid conical end surface, and an annular body of ceramic materialsurrounding said tubular portion and tip member and having a conicalinner wall surface surrounding'and defining a conical combustion chamberinto which said grooves discharge.

15. A gas burner comprising means providing a series offlame-projectingl orifices directed outwardly along a conicalsurface,and means comprising a refractory member having a generally conicalinner wall extending substantially parallel-to the flames .projectedfrom said orifices andv cooper-ating with the first mentioned means toform a conical combustion space substantially closed at its smaller endagainst inflow of air except through said orifices.

16. A gasy burner having at opposite sides thereof flame-projectingorifices directed in lines diverging at an angle substantially less than180, so that-flames projected from said orifices tend to curve towardone another, and a wall vsurrounding a combustion space into which saidorifices open adjacent one end of the space, said space beingsubstantially closedl at said end against fluid flow into the spaceexcept through said orifices, said wall comprising refractory materialhaving its inner surfaces at opposite sides of the burner diverging atsubstantially the same i angle as the orifices and slightly curved so asto parallel said curved flames.

17. A gas burner having a combustion space increasing in cross sectionwith the distance from the bottom thereof and having a combustible airand gas mixture supply chamber extending away from said combustion spaceat the bottom of the latter, and a burner tip member having a bodyportion extending into Asaid chamber and an en larged head portion insaid combustion space,

the wall of said chamber and said member hav-- ing contacting surfaces,one of said surfaces being grooved to form a multiplicity of supplychannels through which the combustible mixture passes into said spacefrom said chamber, said channels opening to said space at distributedpoints adjacent the margin of a bottom portion of said space so thatchannels may form burning jets respectively adjacent and alongsidesections of the wall of said space extending away from its said bottomportion, and including refractory material forming the said wallsections so that the latter are adapted to be hea-ted to incandescenceby said jets, the discharge end portions of said channels and saidtubular portion surthe mixture discharged by said wall sections beingrelatively shaped and disposed to avoid impingement of the inner flamecone portions of the burning jets'against said wall sections.

. 18. A gas burner having a combustion space increasing in cross sectionwith the distance from the bottom thereof and having the bottom wall ofthe combustion space formed with an opening outwardly flared-to providean inclined seat surface, and including means forl passing' acombustible air and gas mixture into said space comprising a burner tipmember having a body portion extending into said opening and an enlargedhead portion in said combustion space, and formed with a surface adaptedto fit against said seat surface, one of said surfaces being grooved toform a multiplicity of supply channels through which the mixture passesinto said space, said channels opening to said space at distributedpoints adjacent the margin of a bottom portion of said space, so thatthe mixture discharged by said channels may form burning jetsrespectively adjacent and alongside sections of the wall of said spaceextending away from its said bottom portion, and including refractorymaterial forming the said wall sections so that the latter are adaptedto be heated to incandescence by said jets, the discharge end portionsof said channels and said wall sections being relatively shaped anddisposed to avoid impingement of the inner flame cone portions of theburning jets against said wall sections.

19. A gas burner having a combustion space increasing in cross sectionwith the distance from the bottom thereof and having a combusf tible airand gas mixture supply chamber extending away from the bottom of thelatter, and a burner tip member having a hollow body portion extendinginto said chamber and an enlarged head portion in said combustion spaceand formed with kerfs which extend through a wall of said hollow body ofsaidl the burner combustion space at tion, and including refractorymaterial forming the said wall sections so that the latter are adaptedto be heated to incandescence by said jets, the discharge end portionsof said channels and `said wall sections being relatively shaped anddisposed to avoid impingement of the inner flame cone portions of theburning j ets against said wall sections.

20. A gas burner having a combustion space increasing in cross sectionwith the distance from the bottom thereof and having a combustible airand gas mixture supply chamber communicating with and extending awayfrom said combustion space at the bottom of the-latter, and a burner tipmember extending across said chamber at the combustin space side of thelatter and comprising a, metallic portion and refractory material at theside of said metallic portion remote from said chamber, and having saidmetallic portion shaped to provide a multiplicity of supply channelsthrough which combustible mixture passes into said space from saidchamber, said channels opening to said space at distributed pointsadjacent the margin of a bottom portion of -said space, so that themixture discharged' by said channels may form burning jets respectivelyadjacent and alongside sections of the wall of said space extending awayfrom its said bottom portion, and including refractory material formingthe said wall sections sovthat the latter are adapted to be heated toincandescence by said Jets, the discharge end portions of said channelsand said wall sections being relatively shaped and disposed to avoidimpingement of the inner flame cone portions of the burning jets againstsaid wall sections.

21. A gas :burner as specified in claim 17, in which the burner tipmember is formed/frefractory material andthe channels through which thecombustible mixture passes into the combustion space are formed bysurface grooves in the body portion and at the underside of the headportion of said burner tip member.

22. A gas burner having a cup shaped combustion space and having anopening circular in cross section in the bott-om wall of said space andPincluding means for passing a combustible air and gas supply mixtureinto said space through said opening comprising a 4burner tip member ofrefractory material, circular in cross` section, and comprising a bodyportion extending into said opening and an enlarged head in saidcombustion space and having surface grooves forming a multiplicity of.supply channels through which said mixture passes from said chamberinto said space, said channels opening to said space at points adjacentthe bottom, Vand distributed about the axis, of said space, so that themixture entering the space through the different channels may formburning Jets respectively adjacent and alongside corresponding sectionsof the wall of said space which extend away from the bottom of thelatter, and including refractory material forming the said wallsections.

so that the latter are adapted to be heated to incandescence by saidjets, the discharge end portions of said channels and said wall sectionsbeing relatively shaped and disposed to avoid impingement of the innerflame cone portions of 5 the burning jets against said wallsections.

23. A gas burner having a trough shaped combustion space increasing incross section with the distance from the bottom thereof, and having a,combustion space bottom wall' formed with a 10 slot and with aninclined'surface at each side of the slot at the combustion edge of thelatter and including means for passing combustible air and gas mixtureJets into said space through said slot comprising a burner tip memberhaving a body portion extending into said slot and an enlarged headportion in the combustion space and formed with a surface at each sideof the slot parallel to. and in abutting relation with the correspondinginclined surface, one of the said surfaces at each side of the slotbeing grooved to form a multiplicity of supply channels through whichthe said combustible mixture jets are passed into said com-bustionspace, said supply. channels opening to said space at points distributedalong opposite sides of a bottom portion of said space so that themixture discharged by said channels may form burning jets respectivelyadjacent and alongside sections of the side walls of said spaceextending away from its said bottom portion,l and including refractorymaterial forming the said wall sections, which are adaptedl to be heatedto incandescence by said jets, the discharge end portions of saidchannels and said wall sections being relatively shaped and disposed toavoid impingement of the inner flame cone portions of the burning jetsagainst said wall sections.'

FREDERIC 0. I-IESS.

